4 papers · 1 filter
Exorcising ghosts with gravitational waves: cases of ghostful and ghost-free fourth-order gravity
Gaetano Lambiase, Shinji Mukohyama, Tanmay Kumar Poddar +1
General Relativity (GR) is an effective field theory valid in the infrared regime. Quadratic curvature extensions intended to probe ultraviolet physics generically propagate a mass…
Limits on New Lorentz-violating Bosons
P. Carenza, J. Jaeckel, G. Lucente +3
We obtain novel constraints on new scalar fields interacting with Standard Model fermions through Lorentz-violating couplings, bridging searches for scalar particles and Lorentz-sy…
Impact of the cosmic neutrino background on black hole superradiance
Gaetano Lambiase, Tanmay Kumar Poddar, Luca Visinelli
We assess the effect of the Cosmic Neutrino Background (CB) on superradiant instabilities caused by an ultralight scalar field around spinning black holes (BHs). When the scala…
Primordial gravitational waves from spontaneous Lorentz symmetry breaking
Mohsen Khodadi, Gaetano Lambiase, Leonardo Mastrototaro +1
We study the effect of Spontaneous Lorentz Symmetry Breaking (SLSB) on Primordial Gravitational Waves (PGWs) generated during inflation. The SLSB is induced by a time-like Bumblebe…